1. Field of the Invention
The present invention relates to capping bottles. More particularly this invention concerns an automatic machine for capping bottles or the like.
2. Background of the Invention
A standard bottle-capping machine has a conveyor that displaces a row or several rows of filled bottles with their necks open upward through a fitting station below a rotor rotatable about a horizontal axis. This rotor has a plurality of radially projecting arms each with an outer end forming a seat that is connectable to a vacuum line. A downwardly open magazine fixed above the rotor holds a stack of caps. The seat-forming outer ends of the arms are constructed to move radially on the arms by means of a complex actuator system so that, when each arm is below the magazine, its end can extend outward and pick a cap off the bottom of the stack in the magazine and then retract inward to pull it from the magazine and, when each arm is in the fitting station, the end can extend again to fit the cap to the bottle beneath it and then retract once the cap is solidly mounted on the bottle. The caps are made primarily of a metallic foil so they can be crimped onto the open mouths of the bottle necks.
Such a machine is quite complex. The arms, which can be provided in, for instance, six rows, are all complicated mechanisms that all must function perfectly every time or the entire machine is down. Hence the machine is very expensive and must be meticulously maintained to ensure that every cap is perfectly fitted.
It is therefore an object of the present invention to provide an improved bottle-capping machine.
Another object is the provision of such an improved bottle-capping machine which overcomes the above-given disadvantages, that is which is relatively simple but which still functions surely and smoothly.
A machine for applying caps to bottles has according to the invention a rotor rotatable about a substantially stationary horizontal axis and having two radially oppositely outwardly directed arms each having an outer end formed as a seat adapted to hold one of the caps. The seats orbit on rotation of the rotor through a fitting station underneath the axis and through a pick-off station above the axis. A conveyor moves the bottles through the fitting station with necks of the bottles directed upwardly toward the axis. A downwardly open magazine holding a stack of the caps in the pick-off station is vertically displaceable between a lower position with the stack engageable with the seat in the pick-off station and an upper position with the stack clear of the seat in the pick-off station. A vertically displaceable element engageable with the cap on the seat in the fitting station can move between and upper position and a lower position for stripping the cap from the seat in the fitting station and applying it to the neck of a bottle in the fitting station. The element and magazine are coupled together for joint vertical movement between the respective upper and lower positions. A drive jointly displaces the stack and element for simultaneously engaging the stack with the seat in the pick-off station and stripping the cap from the seat in the fitting station.
Thus the rotor can be a relatively simple structure, with each arm being an essentially rigid, one-piece part whose outer end forms the seat which cannot move relative to the stationary rotor axis. Instead, the magazine and the stripping/crimping element are moved.
Structure constituted as a frame couples the magazine to the element. This frame is fixed to the magazine and downwardly directly engageable with the element.
In accordance with the invention means is provided for aspirating air through the seats and thereby adhering the caps thereto. Once an arm is in the fitting station above the bottle to be capped, the vacuum can be cut to allow the cap to be stripped easily from the seat and pushed down on the bottle.
The stripping element according to the invention is a respective sleeve surrounding an outer end of each of the arms and radially displaceable between an outer position projecting radially outward past the seat and an inner position radially inward of the seat. The sleeve has a radially outwardly projecting flange that is engaged by the frame as it is bumped down to lower the magazine. To further simplify the structure respective springs on each arm biasing the respective sleeves radially inward. The sleeve is shaped to crimp the caps around the bottle necks.
The arms are diametrically offset from each other relative to the axis. Normally there are a plurality of such arms equiangularly offset from each other. The machine further has according to the invention a drive for displacing the rotor through angular steps equal to the angular spacing between the arms.